Download presentation
Presentation is loading. Please wait.
Published byJasmine Ward Modified over 9 years ago
1
Chapter 19 Pretest Current and Resistance
2
1. A current of 5.0 A moves for 10 s. What total charge passes?
3
I = q/t It = q 5.0 x 10 = q 50 C = q
4
2. A 60 Ω resistor carries 7.0 A. What is the potential difference across this resistor?
5
V = IR V = 7.0 x 60 V = 420 V
6
3. List 4 things that affect resistance of a conductor. What effect do they have?
7
1. Length - the longer the wire, the higher the resistance 2. Cross section – the “fatter” the wire, the lower the resistance 3. Material – some materials are better conductors than others 4. Temperature – the higher the temperature, the higher the resistance
8
4. A 600 W stove has a current of 15 A. What is the potential difference across the stove?
9
P = IV 600 = 15 V 40 V = V
10
5. A microwave draws 5.0 A when connected to a 120 V outlet. If electrical energy costs $0.090/kWhr, what is the cost of running the microwave for exactly 6 hours?
11
P = IV P = 5 x 120 P = 600 W 600 W / 1000 = 0.600 kW 0.600 kW x 6 hours = 3.6 kWh 3.6 kWh x 9 cents = 32.4 = 32 cents
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.